Suction box for paper machines, pulp-drying machines, and the like



Jan, 6,

J. D. ULLGREN SUCTION BOX FOR PAPER MACHINES, PULP DRYING MACHINES, AND THE LIKE Filed Aug. '7, 1922 Led dlnven for n' X/DMAJ W l} a [Y Patented Jan. 6, 1%25.

JOHAN DANIEL ULLGREN, 0F STOCKSUND, SWEDEN, ASSIGNOR TO AKTIEIBOLAGET KARLSTADS MEKANISKA VERKST AD, OF KABLSTAD, SWEDEN, A COMPANY OF SWEDEN.

SUCTION BOX FOB PAPER MACHINES, PULP-DRYING MACHINES, AND THE LIKE.

' Application filed August 7, 1922; serial in). 580,015.

To all whom it may concern:

Be it known that I, JoHAN DANIEL ULL-- roller or rollers is or are provided with approximately circumferentially extendin slots, grooves, or similar recesses, and the invention is principally characterized by that the upper edges of the suction box, as well as intermediate pieces provided between the rollers, reach closely to the surface or surfaces of the roller or rollers, for the purpose that the suction shall be restricted. to act substantially only on such portion or portions of the wire screen which is or are directl supported by the roller or rollers.

- In t e accompanying drawing Fig. 1 illustrates dia rammatically an embodiment of the invention with a slotted roller. Fig. 2

shows an embodiment having three slotted rollers.

Referring to Fig. 1, the wire screen 1 with the web of material carried by the same runs over the suction box 2, before it arrives to the couch press 3, 4. A roller 5 is rotatably journalled in the suction box 2 in such manner that its upper surface is approximately on a level with the upper edges of the suction box. The roller 5 is provided with slots 6, grooves or similar recesses. As shown in the drawing, the upper edges 7 of the suction box on either side of the roller reach closely to the surface of the roller, on account of which the suction will be practically limited to only the portion of the wire screen directly supported by the roller, so that the adjacent portions of the wire screen will not be pulled down by the suction, and consequently, friction of the wire screen against the edges of the box will be avoided. The box 2 communicates through asuction conduit 8 with a suitable suction means, so that a suitable vacuum is maintained in the box.

According to Fig. 2 there are three rollers 13 in the suction box 12, whichrollers are also provided with slots or the like; Between said rollers there are provided side pieces 14 which extend straight across the box and form edges reaching closely to the surfaces of the rollers and corresponding to the edges 15.

Owing to the arrangement according to the invention that the upper edges of the suction box, as well as the pieces intermedi ate the rollers, reach closely to the surface or surfaces of the roller or rollers which is or are provided with approximately circumferentially extending slots, grooves, or similar recesses, the suction is not only extended over practically the whole of that part of the surface of the roller which is in contact with the wire screen and thus affects an efficient removal of liquid from the wire screen and from the web of material carried b said screen, but the action of the suction wi 1 also be practically limited, as above stated, to only the part of the wire screen which is direct y supported, so that a pulling down of the wire screen by the suction is avoided, which otherwise would result in the wire screen being pressed against the rigid edges of the suction box, or against the intermediate pieces, consequently producing a considerable friction. Accordin :to the resent invention the wire screen Wlll thus e supported and carried by the rotary roller during the entire passage of the screen through the field of suction.

The suction box according to the present invention is also particularl adapted for use as guide or regulating rol er for the wire screen. As is well known, there is generally used under the wire screen immediately in front of the couch press, a guide or regulating roller which is journalled at each end in bearings which are adjustable in the longitudinal direction of the wire screen, so that by adjusting said roller more or less obliquely to one side or the other inrelation to the direction of travel of the screen it is possible to make the screen move to one side or the other. If the present suction box is arranged so as to be adjustable in the said manner it will form a very effective guide or regulating roller for the reason that by the wire screen being sucked against the roller the engagement between the screen and the roller becomes more secure, so that the roller may better guide the wire screen in the desired direction. Such adgnstability of the suction box may be efiecte in an easy manner by making the box slidable, at least at one end, on a support '16 and connecting the box to said support by means of ascrew 17 provided with .ahand wheel 18 by means of which screw the box may be moved on the support in the longitudinal direction of the wire screen. 7

I claim:

1. In a suction box of the character described the combination of a box, means for applying suction to said box, and at least one roller rotatable journalled in said box and provided with circumferential slots in its surface, the upper edges of the box reaching closely to the surface of the roller, for the purpose that suction shall be applied submenacestantially only to the portion of the wire screen directly supported by the roller. 4

2. In a suction box of the character described the combination of a box, means for applying suction to'said box, rollers rotatably journalled in said box and provided with circumferential slots in their surfaces, and intermediate pieces between said rollers, the upper "edges. of the box and said intermediate pieces reaching closely to the surfaces of the rollers, for the purpose that suction shall be applied substantially only to the portions of the wire screen directly supported by the rollers.

3. A suction box according to claim 1, ar-' ranged so as to be adjustable and used as guide or regulating roller.

' JOHAN DANIEL ULLGREN. 

